Radiodetector



Nov. ll, 1930. c. K. s'RoBEL RADIO DETECTOR Filed sept. 2'?, 1928 J m w b T 0 T r A Tf S M Ki QQ INVENTOR Patentedr Nov. 11, 1930 v www.'lsraessrarte@me l CHARLES x. sTRoBEL, or ,rrTTsBURGiL PENNsYLvANIaAssIGNoN 'ro `THEUNION Y `coating C may be formed thereon in any suit- 'swIToH & srGNAI.l PENNSYLVANIA Y RAnronETiiciio i Appiication iea september 27,' 19a-8.* serial No. 308,689.

S method for preparing each of such forms, and

will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. l is a View showing, in side elevation, one formof radio. detector prepared in accordance with my invention. Figs. 2, 3 and 4L are similar views showing another form of radio detector embodying my invention as it appears at different stages in the process of manufacture. Fig. 5 is a view showing, in side elevation, the detector illustrated in Figs. 2, 3 and 4:, as it appears when completed. Fig. 6 is a, View showing, in side elevation, the completed detector illustrated in Fig. 5 arranged for mounting. Similar reference characters refer to similar partsiii each of the views.

Referring first to Fig.` l, the reference tector lcomprising a core, or bar B, of metal having a -coating C of a compound of the metal formed thereon. For example, the bar B may be copper, and the compound of the metal may be cuprous oxide. The bar B may have any convenient size or shape, and the able manner. If the bar B consists of a bar of copper l X la X fr, a suitable coating of cuprous oxide may be formed thereon by `heating the bar at a temperature of -approximately 18700 F. for about twelve hours, and then allowing the bar to cool at atmospheric temperature. If a different size bar, or a different'temperature is used, it may be necessaryv to heat the bar for a dierent length of time. After the bar has cooled, a portion of' the oxide coating is broken away as indicated at E, to expose a portionof the bar. A fixedconnection is then made to the exposed porf-tion of the bar B by means of a wire l. An

adjustable connection is also made to the detector A by meansof a fine wire 2, commonly known as al cat-Whisker.l The end of the wire 2 is brought into contact with the crystalline structure ofthe voxide coating atV la.

portions JandK ilmof'm'etalli'c copper, and a band L of its cleaiijsurface, such ,as theedgeof thev broken ofthe oxide may be broken away as indicated at D, an'd theend of the wire Q "inay be brought into `contact with' thel crystalline structure of the oxide coating this surface, as shown inthe drawing. l

I have found structed Vin this manner possesses -rectify'ving properties `which are comparable withsthejy propertiesof any of the heretofore known types of crystal' detectors havingk rectifying at the edge' @f1 that a' radiov Adetector icon# I COMPANY, or' swissvAriiii, rENNsYLvANIA, A com?,oRA'iroNoiry r Vportion nor; if desi-maa seeonafporasn' f asymmetric current characteristics, andthis" radio detectormay be used in thee-same cirff cuits as the heretofore knowntypesgof crys-v tal detectors.

Furthermore, `a .detector lconstruc'ted in `this ina'nner is vsta-lo"le,`fand is ycoinv 'ln'constructingthe detector shown i 2, 3,4 and 45, I'einploy a' copper blank having tapered portion 3 at Aone end." vThis V bar "is heated ina'v furnace ata suitable,tem-KY I n perature,si ichvfor example, fas 1810? F.',"unti l character A designates ingeneral a radio dethe bjarjisfcompletely oxidized, and the barlis then allowed'to cool atatmospheric ftemp'era` used, the bar may ,be completely oxidizedjviii ,The bar then. appears,Y as

about fsix hours.

Vshown fimFig. 3, and i is "designated by the reference character G. Innext reduce the sur-v.

faceo'f the oxidizedba'r G to metallic copper in ltwoA portions,

islnot reduced, and which, preferably havea considerable difference in area.

which are separated from' eachother by a narrow band of surface which se., Y

sa; n

plishthisresult, l cover the bar ,G near; the

infasuitable electrolyte, such as dilutfesulvelectrolyte from vsuitable anode by immersingthe bar in hot water.` The bar then'ap'pears `as shown in Fig. 5, and has two of its surface coated with a 1mb',

pur'e"copper,",until aV coating "or film-"of Inetalliopoppen-having the desired thickness-is obtained; The parailin band is thenIeIIlQVed' 9a l phur'ic 'acid,fandpass a current throughfthe, A

. toi-hete.; as amcathodejthereby reducingtheoxideto Chhhichuyfuggee Theiowgrhsihthhdirec-j. f

'i Y Snrfac'e which is not Coated. vElectrical c'onnectionsare thenmade to thedetector by a Wire 5 soldered to the oopperilm of the por v tiony K, and a Wire 4j soldered to the Copper film of the portion J.

It is'V sometimes desirabl'eto` arrange'the f vdetector in a manner convenient formounting. `For-this purpose I have provided a glass, tube M having ltwo metallic end caps N.

P.. (see :Fi 6);:` Theldeteetor' isf firstfy 'i p :placed inth'eltn le M. One end l'capN is then I .n

soldered to the Wire 5, and the'other end cap reduced to metallic copper with the exception of afsmall band surrounding the bar nearv the endoftheftapered portion, :L protecting tube surrounding said bar,` electricallyeonx#VV ducting endr caps'se'aledjon said tube', and` means for connecting. the copper ffilm :of the bai'at the opposite endsof the beirvviththevl adjacent end cap..

Pis soldered to the `Wire 4.. The end caps@ i v .are then sealed on'the'glejss tube `ineny 0011-.,A u

vement manner;

detector` yconstructed' in this ynmnner has good rectifying chairecte'rlst-ics,"V and 1s. Ine-- Y tion of suchjadteotor is from the large Yarea of vreduced* copper to the small area.'l I have fond vthat diferent ratios Yof rectification,

Vmaybe obtained by varying-the. ratio/of the small tree of rednced coppercto the'large. area.

Yfl'p'reei' to utzilize ac opper bar. Fhaving a Y. f vtapered end 23g-because this ormof bar ison-Y venient forVA YobtainingY a larg-e `difference in area between `the tvvo reduced portions Jl Although ifhhvh, herein shown and' dhr.

' scribed only two' forms radio detectors ema vbodyi'ngfmy.inventioi,f it is understoodwthat v v'ziriou's'ehanges' and modiications`-`may be made thereinwithint'he 'scope of the appended l bltimsfvvithout dep'giftingl from` the SpiritV 1-j'an"d,scopeofny'invention.'l 'i Y two separate ,polietionsl of thebar having'vdif-.j

ferentarens.

fsa

vehndK. Thisp'rticlai' formy of bei', how t Y i y' i ever, islnot` essential to inylmvention,y

p V","911A"ijzidiofdeteetor oomprising 'yafbr'f l i Ciiprolis' oxidehavin'g 'copper' films formedv vfilm isl separated copper film:V f

taperedportion.y Y Y. 2 Y j radio detectorifcomprising a barof `cpron`s`foxide yhaving 'a tperedfend l and Y f having Moppel? lm'oh' 2111 beta1-,Smell POril f tionfof its"snrfacesaidiportion surrounding i the ber atgthejtztpered end 'in such I'rui'nrie-1;'.1` A that'silonparativelyjsmallaree ofthefeopper'f K Y from the 'remainder 'Qffthely r -HARLESLKL i 

